1. Field of the Invention
The present invention relates to an electron device, which is suitable for single electron transistors utilizing carbon nanotubes which are self-organizing nanostructures, and to an efficient process of manufacturing the electron device.
2. Description of the Related Art
A single electron transistor is a three-terminal element utilizing the single electron effect. The single electron effect is also called the Coulomb blockade effect, and this effect is based on a phenomenon derived from the fact that there exists no smaller quantity of electricity than the unit electric charge amount of an electron. When a capacitor is made to approach the nanometer level in size, the electrons stored in the capacitor can move between the electrodes due to the tunnel effect. However, when the capacity of the capacitor electrodes is extremely small (e.g., about 10−18 farads), the change in the static electric potential, which arises due to one electron tunneling, greatly changes the voltage applied to the capacitor (the tunnel junction). If this change reverses the orientation of the voltage applied to the tunnel junction, the tunnel phenomenon will actually not arise. By using this phenomenon that the tunnel phenomenon does not arise in a finite voltage range, it is possible to make electrons discretely tunnel one-by-one. This is called the single electron effect. A conventional process of manufacturing and a structure of a single electron transistor which utilizes this effect is shown in FIGS. 8A and 8B. In this single electron transistor, a Ti thin film is oxidized locally by AFM anodization using a carbon nanotube AFM cantilever “21” in which a carbon nanotube having a diameter of 1 to 2 nm “23” formed on a silicon tip “22”, and Ti metal islands “24”, “26”, and a Ti oxide film capacitor “25” are formed. In this manufacturing process, because AFM (Atomic Force Microscope) is used, operation at the atom level is possible and the single electron transistor having a size of nano meter level can be obtained, as shown in FIG. 8B. However, because the anodizing phenomenon is utilized for forming the Ti metal islands, there are limits in size reductions thereof. It has therefore been desired to provide a single electron transistor, which can easily be manufactured and can be made even finer, and to provide an efficient process of manufacturing such a single electron transistor.